Marineland Magnum Micron CartridgeMarineland Magnum Micron Cartridge is excellent for polishing your aquarium water. This cartridge will pull out the finest of particles, resulting in a crystal clear aquarium. Replacement cartridge for Marineland Magnum canister filters Pulls out finest particles to polish water Keep aquarium water clear and healthy Can be used with diatomaceous earth, but make sure that your filters instructions specifically state that it is designed to be used as a